2. Corvus caurinus


June 18, 2016

Crows was the second sound I noticed this morning. The first was partiers returning home. Emma has the bedroom again, so Sherryll and I slept in the living room with a front window open. Lots of life happens on Fern Street’s only block. Hundreds of people live here in four-story apartment and condominium buildings, townhouses and a few old wooden houses, circa 1910. We live in one of those, the Friends Meeting House, mid-block. “Friends” comes from the proper name for Quakers, the Religious Society of Friends. As Resident Friend, Sherryll takes care of the building and the rentals to groups who meet here. Generally Fern Street remains decently quiet until six-thirty or seven, but the crows got noisy much earlier. Raspy, emphatic, this bird voice I recognize.

Everyone in Victoria knows crows. The term “in-your-face” comes to mind. On strike, many years ago at a school a few blocks from here, I paced round and round the block. Each time around, insulting crows dive-bombed my placard and me as I passed under a tree with a nest. Springtime always brings stories of hats knocked off or scalps scratched.

Our crow species on Vancouver Island is the Northwestern, Corvus caurinus. Or maybe not. New genetic studies may be changing the picture. Northwestern crow looks identical to American crow, just slightly smaller. My bird books assure me that American crow stays away from British Columbia’s coastal islands and keeps generally east of the Coast Range mountains. That belief might be wrong.

Corvus caurinus translates as “the crow of the northwest wind”. Its evolution as a separate species has occurred recently, within the last 400,000 years, during ice ages. Glacier has periodically advanced and retreated during that time period.  Sometimes it has burdened almost all of British Columbia, from the Rockies to the ocean. Only a few fragments of coastline have remained free of ice. In the most recent advance, for example, between 25,000 and 11,000 years ago, glacier covered the coast here at Victoria, but bits of ice-free seashore persisted at such spots as Naikoon Peninsula on the islands of Haida Gwaii, and likely on Vancouver Island’s Brooks Peninsula. Such places became refugia, where many animal and plant species survived. Crow populations likely persisted there, isolated for millennia, adapting and evolving into Corvus caurinus – shoreline foragers.

On the ebb tide they combed the beaches and rocks. Fish, living or dead, crabs and shellfish became their staple foods. They learned to dig clams, fly up and drop them on rocks to smash open. High tide forced the crows onto dry land to forage berries and bugs, and to eat seafood they had cached during low tide. When humans arrived, Northwestern crow learned to watch for edibles that we left unguarded.

British Columbia coastline has included human camps and villages for many thousand years. Some scientists argue for sixteen or seventeen thousand. People were moving south from Beringia, the land that linked Alaska and Siberia during the most recent ice age. In the coldest millennia, ocean levels lowered drastically because glaciers held much of the planet’s water. Huge areas of continental shelf dried out. Where the Bering Straits now separate Asia and North America, low sea level exposed a land corridor 1,500 kilometres wide. Extreme dry climate kept much of it free of glacier. Humans migrated there from Asia and survived its harsh tundra conditions. People from Beringia traveled south, populating our continent. Some came down the Pacific coast.

Did we migrate by land or by sea? Scientists have debated. If boats carried us, then we may have arrived as long ago as 17,000 years, and settled the coastal refugia. Evidence would be hard to find, however. More than a hundred metres of water now submerges those shores where we and the Northwestern crow may have dug clams. Certainly “the crow of the northwest wind” has long since learned to scout for edibles that people might leave unwanted or unattended. Stealing our sandwich from the picnic table and rummaging our village midden are ancient high-tide behaviours.

As the planet warmed and glaciers retreated, Northwestern crows from the refugia could extend their range north and south along the shore. They would meet American crows that were moving up from the south and would interbreed. Recent genetic studies suggest a long coastal zone where Northwestern and American crow genes have been mixing completely. Victoria might be sitting in the middle of that zone. Pure Northwestern crow genes may persist along the Alaska coast, and pure American crow genes on the California coast, but our population on Vancouver Island appears share both ancestries. What should we call them?

I have wondered when crows first arrived in Victoria. Here at the Quaker Meeting House on Fern Street, when did crows first converse? In Victoria the glacier that covered us in the recent ice age was gone around 15,000 years ago. We were under water though.

The weight of the ice had depressed our bedrock possibly two hundred metres. It takes some imagining. The rock that outcrops in the Meeting House front yard would not easily squish down, one would think. To make sense of it, I remind myself that this rock may be solid, but it’s not so thick. Our bedrock is a thin skin on the planet, maybe ten or twenty kilometres deep. The next layer down is more plastic, semi-molten. Our bedrock floats upon it.

Floating brought Vancouver Island here. Our journey began south of the equator 300 million years ago. Volcanoes under the ocean built islands and archipelagos. The plate of bedrock of which they were part drifted north, slowly. The islands collided with North America 100 million years ago along the Oregon shore. Then, in the slowest of slow-motion shipwrecks, they bumped and scraped north along the coast, leaving bits behind. Vancouver Island was one piece of the wreckage. The Islands of Haida Gwaii, another. The final pile-up added mountains to southeast Alaska.

So yes, I can imagine that glacier depressed this floating bedrock. When the ice went away, Victoria’s downtown lay maybe seventy-five metres submerged, but Fern Street is higher than downtown. Probably forty or fifty metres of water covered our block. When did Fern Street emerge from the sea?

Our bedrock, free of glacier burden, rebounded upward. Sea level was also rising as continental ice continued to melt. In the vertical race between our bedrock and the ocean, we moved faster. Sometime between 15,000 and 14,000 years ago, Fern Street pulled out above the water. We sat on the shore of a small island, looking out across sea surface and other little islands. Crows no doubt foraged at low tide, digging clams in the sand. Did the crows see people? I doubt it. The little rocky island might not yet offer much to attract humans.

Further downhill from the Meeting House, shallow water still covered flat seabed. Land continued to rise. Around 13,500 years ago, our valley fully emerged. A stream picked its path in glacial silt down the valley bottom. These days we call it Bowker Creek. Salmon found it as soon as the ice departed, I suspect.

When glaciers melt, salmon quickly populate the new streams. Scientists observe at Glacier Bay, Alaska, where retreating ice exposes new shoreline every year. A new creek appears. Within a decade, salmon are spawning and crows are picking at carcasses. Life rushes in. Fifty years along, willow and alder grow dense on the streambank; songbirds nest; thousands of salmon crowd the creek mouth.

How about people? When did we find Bowker Valley and this Fern Street hillside? Archaeology has exposed a village site near the mouth of the creek at Oak Bay. It dates back less than 3,000 years, but for sure we have lived here much longer. A salmon stream has meandered several thousand years down a gently-sloping valley to a shore abundant in seafood. People are as observant and opportunistic as crows; we recognize food sources when we see them. Hard evidence is not available though. Our most ancient camps and villages at the creek mouth would now be difficult to locate.

“When and how did people arrive here?” – the question has always challenged Archaeologists on the British Columbia coast. My first wife, Marjorie, worked in the 1970s at digs, which I visited. It surprised me that they uncovered coastal villages far from the coast, riverside camps far from the river. Figuring out when shore was where is so complicated here. So many factors play. Glaciers depress bedrock, then melt; rock rebounds and ocean rises; rivers dig channels and build deltas; floating plates of bedrock drift, collide, shove persistently together, buckle, heave mountain up and trench down. British Columbia shoreline does not stay put.

In the present decade, science has given us a clearer picture of shoreline movements since ice-age glaciers melted. A journal article open now on my computer is Post-glacial sea-level change along the Pacific coast of North America by Dan H. Shugar et. al., from Quaternary Science Reviews online, 2014. Isn’t this a time? Sitting in pajamas at the Meeting House kitchen table with a cup of tea, one can search out information on local sea levels in ancient days. Reading the paragraph about Victoria and looking at the graph, I see Bowker Valley hoist fully out of the sea maybe 13,500 years ago, and continue slowly to rise. Shoreline continues to move down across Oak Bay seabed and beyond, perhaps forty metres below present sea-level. Then, around 11,000 years ago I see water-level rising. The shore gradually moves back inland to its present position a few thousand years ago.

So those first humans who landed our boats at the mouth of Bowker Creek and camped here: where should we look for the campsite? If we arrived before 13.5 thousand years ago, the creek mouth would be somewhere upstream from today’s shoreline. Maybe we camped under the parking lot at Hillside Mall. If we arrived between thirteen thousand and five thousand years ago, our first campfire might now lie somewhere beneath the waters of Oak Bay or Baynes Channel. From generation to generation we likely relocated our camps or villages repeatedly back from the shore as rising water inundated them. Money for Archaeology is scarce. We may never find more ancient camps in Bowker Valley.

Why would I care? What does it matter when Fern Street rose from the sea, or crows arrived, or people? Why would the shifting picture of our restless shoreline delight me? Why, indeed, would Shugar et. al. devote all that research time, brainpower, grant-application effort, love, to pin down Post-glacial sea-level change along the Pacific coast of North America? Partly, they were looking for places to dig holes. It comes back to the question of when and how humans first populated the Pacific coast – where to look for our first villages on shoreline that keeps changing.

The researchers identified a segment of British Columbia shore that stayed put when the glaciers departed, coastline where the various forces, pushing land and sea up and down, all balanced. Archaeologists dug on the shore of Calvert Island, halfway up the BC coast. Humankind dug, I would argue. Forensic human brain delved rectangular pits at the shoreline. Our species has evolved gathered around tracks in the mud, interpreting their story. It keeps us alive. Is food nearby? Is danger? Digging on the beach at Calvert Island, we found, one metre down, a footprint in the clay. Further pits uncovered footprints of three people, a family group around a hearth fire with a stone knife for cutting food. Carbon dating indicates antiquity of more than 13,000 years, the oldest human footprints yet found in North America.

More digging, on Triquet Island nearby, has moved the record of humans on BC’s central coast back further, to 14,000 years ago. It shows that people in boats were quickly populating the shore as the glaciers pulled back.

The pits at Calvert and Triquet Islands: I want to say that Earth dug them. The planet evolves capacity, I want to say, delicately to apply trowel and whisk broom to its own skin. Earth wonders who and what she is. The guy at the Fern Street kitchen table is just a moment of conscious attention Earth applies to her question. He reports: I hear people in Bowker Creek’s valley coming uphill. This is sometime between 13 and 13.5 thousand years ago. I am likely wrong. This is a family from the camp at the mouth of the creek. They explore, hunt, forage today upstream and up this hillside. A crow in the valley watches them and comments. A crow here answers.